Mechanical Test details the laboratory's capabilities for tensile and hardness testing of materials to measure performance under various types of loading as well as metallurgical sample preparation techniques.

Tensile Test
Hardness Test
Metallography

Tensile Test

In tensile test, an increasing force is applied uniaxially along the long axis of specimen at a constant rate. The resulting elongation along this axis is recorded by another device called extensometer. If possible, the specimen is always cut into the dimension and shape proposed by the testing standard. The specimen is usually deformed at a constant rate until fracture. It is a common mechanical test to obtain several important mechanical properties about strength and stiffness of materials including tensile strength, yield strength, Young modulus and the degree of elongation. All of them are important parameters in product design and many materials processes.

Hardness Test

Vickers/Rockwell hardness test
Hardness is a measure of the resistance of materials to localized plastic deformation i.e. penetration on the surface. It correlates well with other mechanical properties like tensile strength and wear resistance.

Rockwell test is one of the most common hardness measurements. Spherical steel balls or diamond cone (for harder materials) of different size (1/16 – 1/2 in.) are employed as indenter. They are forced into the materials surface by a load in the order of kg. The depth of penetration is measured and converted to a hardness number. For harder materials, a higher hardness number would be given as smaller penetration depth would be obtained. Different scales for Rockwell hardness are available and each scale refers to a specific combination of indenter and loading force to fit for materials with different hardness.

Vickers hardness test is a microhardness test. The indenter is a very small diamond pyramid and the load applied is much smaller (1-1000g).A microscope is required to observe the indentation and a relatively flat surface is needed for accurate hardness measurement.

Metallography

Metallography refers to the study of microstructure of metals and metal alloys by a process which consists of a series of finely controlled sample preparation procedures. They include sectioning (cutting), grinding, polishing and etching. As the microstructures of metals and metal alloys are closely related to the mechanical properties of the materials (e.g. hardness), detailed revelation of microstructures is valuable for quality control and failure analysis.